New tool for studying relapsing malaria infections

A new tool could be instrumental in transforming the medical community’s search for novel treatments against relapsing malaria infections.

Researchers at Seattle BioMed recently used a human-chimeric mouse model to further study Plasomdium vivax malaria parasite liver infections. The scientists used this tool to grow livers from humans. They then infection the livers with P. vivax to investigate the parasite’s activity, development and dormancy. They also observed how various treatments impacted each stage of the malaria infection.

P. vivax malaria parasites, which are the most common malaria parasite in the Asia-Pacific and American regions, have a stronger resistance to treatments compared to other malaria parasites. This is because these parasites go into dormancy immediately after infecting the liver. They can remain dormant for months or even years. When they do become active, they replicate until they fill the blood stream. At this point, the patient relapses into malaria.

“Unfortunately, the only drug we currently have in our arsenal to eliminate these dormant malaria stages is primaquine, which needs to be taken for 14 days and can have severe side effects,” Ivo Mueller, a leading malaria expert at the Walter and Eliza Hall Institute in Melbourne, Australia, said. “Due to these complications, better drugs and eventually vaccines to fight against dormant P. vivax are urgently needed.”

Mueller said the new model is a game changer.

“For the first time, we now have a realistic opportunity that not only allows us to directly study this normally hidden P. vivax life stage, but also to test new drugs and vaccines," Mueller said. "This new model is an essential resource in our quest to develop the new anti-vivax interventions that we will need to eliminate P. vivax malaria.”